[PATCH 1/3] smb: client: refactor ACL setting control flow in id_mode_to_cifs_acl()

[PATCH 1/3] smb: client: refactor ACL setting control flow in id_mode_to_cifs_acl()

[Steve French]

From: Ralph Boehme <slow@samba.org>

Refactor the control flow in id_mode_to_cifs_acl() to reduce nesting and
prevent error code overwriting.

Instead of wrapping the call to ops->set_acl() in a conditional block,
introduce early exits (goto id_mode_to_cifs_acl_exit) when build_sec_desc()
fails or ops->set_acl is NULL. This ensures that any actual error returned
by build_sec_desc() is not overwritten with -EOPNOTSUPP.

Signed-off-by: Ralph Boehme <slow@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
---
 fs/smb/client/cifsacl.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/fs/smb/client/cifsacl.c b/fs/smb/client/cifsacl.c
index 42a3115359da..5bbf73736358 100644
--- a/fs/smb/client/cifsacl.c
+++ b/fs/smb/client/cifsacl.c
@@ -1834,14 +1834,18 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 *pnmode,
 
 	cifs_dbg(NOISY, "build_sec_desc rc: %d\n", rc);
 
-	if (ops->set_acl == NULL)
-		rc = -EOPNOTSUPP;
+	if (rc != 0)
+		goto id_mode_to_cifs_acl_exit;
 
-	if (!rc) {
-		/* Set the security descriptor */
-		rc = ops->set_acl(pnntsd, nsecdesclen, inode, path, aclflag);
-		cifs_dbg(NOISY, "set_cifs_acl rc: %d\n", rc);
+	if (ops->set_acl == NULL) {
+		rc = -EOPNOTSUPP;
+		goto id_mode_to_cifs_acl_exit;
 	}
+
+	/* Set the security descriptor */
+	rc = ops->set_acl(pnntsd, nsecdesclen, inode, path, aclflag);
+	cifs_dbg(NOISY, "set_cifs_acl rc: %d\n", rc);
+
 id_mode_to_cifs_acl_exit:
 	cifs_put_tlink(tlink);
 
-- 
2.53.0

[PATCH 2/3] smb/client: fix security flag calculation when setting security descriptors

[Steve French]

From: Ralph Boehme <slow@samba.org>

In id_mode_to_cifs_acl(), aclflag was initialized to CIFS_ACL_DACL by default.
This forced the client to request setting the DACL even when only an ownership
(chown) or group (chgrp) change was being performed.

Let build_sec_desc() do the proper flag calculation by initializing aclflag
to 0. build_sec_desc() sets the appropriate bits (CIFS_ACL_OWNER, CIFS_ACL_GROUP,
or CIFS_ACL_DACL) depending on what actually changed.

If build_sec_desc() results in aclflag being 0 (meaning no changes were mapped),
exit early to avoid sending an empty security descriptor update to the server.

Signed-off-by: Ralph Boehme <slow@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
---
 fs/smb/client/cifsacl.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/smb/client/cifsacl.c b/fs/smb/client/cifsacl.c
index 5bbf73736358..535f3e8d6b92 100644
--- a/fs/smb/client/cifsacl.c
+++ b/fs/smb/client/cifsacl.c
@@ -1738,7 +1738,7 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 *pnmode,
 			kuid_t uid, kgid_t gid)
 {
 	int rc = 0;
-	int aclflag = CIFS_ACL_DACL; /* default flag to set */
+	int aclflag = 0;
 	__u32 secdesclen = 0;
 	__u32 nsecdesclen = 0;
 	__u32 dacloffset = 0;
@@ -1837,6 +1837,11 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 *pnmode,
 	if (rc != 0)
 		goto id_mode_to_cifs_acl_exit;
 
+	if (aclflag == 0) {
+		cifs_dbg(FYI, "set_cifs_acl aclflag=0, no change mapped\n");
+		goto id_mode_to_cifs_acl_exit;
+	}
+
 	if (ops->set_acl == NULL) {
 		rc = -EOPNOTSUPP;
 		goto id_mode_to_cifs_acl_exit;
-- 
2.53.0

[PATCH 3/3] smb/client: fix chown/chgrp with SMB3 POSIX Extensions

[Steve French]

From: Ralph Boehme <slow@samba.org>

Ownership (chown) and group (chgrp) modifications were being ignored when
mounting with SMB3 POSIX Extensions unless CIFS_MOUNT_CIFS_ACL or
CIFS_MOUNT_MODE_FROM_SID were also explicitly set.

Fix this by checking for posix_extensions in cifs_setattr_nounix() when
updating UID and GID, ensuring that id_mode_to_cifs_acl() is called to map
and set the ownership/group information on the server.

Cc: stable@vger.kernel.org
Signed-off-by: Ralph Boehme <slow@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
---
 fs/smb/client/inode.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c
index 51fb7c418d52..56b0f109e41b 100644
--- a/fs/smb/client/inode.c
+++ b/fs/smb/client/inode.c
@@ -3376,7 +3376,8 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
 	if (attrs->ia_valid & ATTR_GID)
 		gid = attrs->ia_gid;
 
-	if (sbflags & (CIFS_MOUNT_CIFS_ACL | CIFS_MOUNT_MODE_FROM_SID)) {
+	if ((sbflags & (CIFS_MOUNT_CIFS_ACL | CIFS_MOUNT_MODE_FROM_SID)) ||
+	    cifs_sb_master_tcon(cifs_sb)->posix_extensions) {
 		if (uid_valid(uid) || gid_valid(gid)) {
 			mode = NO_CHANGE_64;
 			rc = id_mode_to_cifs_acl(inode, full_path, &mode,
-- 
2.53.0